Recently, electronic devices are increasing which have convergence functions compositely performing one or more functions.
One such example electronic device, a mobile terminal called a ‘smart phone’, is mainly used. In particular, such a mobile terminal includes a large screen touch type display module. Besides a basic function of communication with an opposite party, the mobile terminal includes a high pixel camera module capable of capturing a still image and a video. In addition, the mobile terminal can play multimedia content such as music or video, and can access a network and perform Internet surfing. Such a mobile terminal includes a high performance processor and is advanced to rapidly perform various convergence functions. Accordingly, the main function of communication with another party seems to be rather an additional function.
Improvements to electronic devices include efforts to reduce a specific absorption rate (SAR), which is a numerical expression of an electromagnetic wave absorbed by a human body. For example, during use of an electronic device, since a high measurement value of absorption power per unit mass of an electromagnetic wave absorbed by a human body may badly affect the human body, every country restricts the electromagnetic wave SAR for the head portion of a human body to be not greater than a reference value. The maximum allowed electromagnetic wave SAR in Korea is 1.6 W/Kg which is identical to that of the US; Europe and Japan have a greater value of 2.0 W/Kg.
Typically, the electronic device may adjust the electromagnetic wave SAR by adjusting a transmission output value thereof, but an adjustment time of the transmission output value is determined dependently on a sensor.